KR20160066363A - Organic light emitting display device and method of manufacturing the same - Google Patents

Abstract

Provided is an organic light emitting display device. The organic light emitting display device includes a lower substrate. An inorganic layer is placed on the lower substrate. A first pad electrode is placed on the inorganic layer. A passivation layer is placed to cover a side part of the first pad electrode. A second pad electrode is placed on the passivation layer, and electrically connected to the first pad electrode. A conductive film layer is placed on the second pad electrode. A circuit substrate is placed on the conductive film layer. An upper sealing layer is placed on the circuit substrate and the passivation layer. A lower sealing layer is placed on a lower part of the lower substrate. According to an embodiment of the present invention, the organic light emitting display device is capable of suppressing a roll-up phenomenon of the lower substrate by providing tensile stress to the lower substrate in the pad area.

Description

Technical Field [0001] The present invention relates to an organic light emitting diode (OLED) display device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display and a method of manufacturing the same, and more particularly, to an organic light emitting display and a method of manufacturing an organic light emitting display in which curling of a pad region is suppressed in a flexible organic light emitting display .

The organic light emitting diode (OLED) is a self-emissive type display device, and unlike a liquid crystal display (LCD), a separate light source is not required, so that it can be manufactured in a thin and various shapes. Further, the organic light emitting display device is not only advantageous from the viewpoint of power consumption by low voltage driving, but also excellent in color implementation, response speed, viewing angle, and contrast ratio (CR), and is being studied as a next generation display.

Recently, organic light emitting display devices have been studied as flexible organic light emitting display devices having a rounded surface or bending as a next generation display. In the flexible organic light emitting display, at least one of the upper substrate and the lower substrate includes a flexible substrate, which is excellent in ductility. For example, the flexible organic light emitting display may include a lower substrate made of a PI (polyimide) material, wherein PI is excellent in ductility.

However, due to the flexible characteristics of the lower substrate, there is a problem that it is difficult to handle when the lower substrate is moved and deposited in the manufacturing process of the flexible organic light emitting display. Accordingly, a glass substrate having excellent rigidity can be disposed under the lower substrate to support the shape of the lower substrate, and the deposition process can be performed. Thereafter, the glass substrate can be removed to fabricate a flexible organic light emitting display . Here, the use of a glass substrate for supporting the lower substrate has a problem that the glass substrate is cracked or cracked during the manufacturing process of the flexible organic light emitting display device, and the lower substrate is curled down while the glass substrate is being removed have.

Also, deformation may occur on the lower substrate made of PI during the high-temperature deposition process requiring heat on the lower substrate. Specifically, the coefficient of thermal expansion between the inorganic layer disposed on the lower substrate and the lower substrate is different, and the lower substrate may expand larger than the inorganic layer during the high-temperature deposition process. Accordingly, the organic light emitting display panel is dried below the lower substrate while the lower substrate shrinks in the process performed at room temperature after the high temperature process. Particularly, in the flexible organic light emitting display having a large area, the phenomenon in which the lower substrate is curled from the pad region occurs, and the active region can be partially dried. Accordingly, it is difficult to attach the lower film to the lower portion of the active region.

Accordingly, there is a need for an organic light emitting display device and a method of manufacturing the organic light emitting display device that can suppress the phenomenon of the lower substrate being curled in the pad region of the flexible organic light emitting display device.

[Related Technical Literature]

One. An organic light emitting display having improved power supply wiring structure (Patent Application No. 10-2010-0137217)

2. A display element which is electrically connected to the FPCB (Patent Application No. 10-2012-0149820)

The inventors of the present invention have proposed an organic light emitting diode display device in which an encapsulation layer is disposed in a pad region in order to solve the problem that a lower substrate is dried downward of a lower substrate while removing a glass substrate from a lower substrate in an organic light emitting diode Invented a new structure and a manufacturing method thereof.

Accordingly, it is an object of the present invention to provide an organic light emitting display device and a method of manufacturing an organic light emitting display device, which can suppress the phenomenon that a lower substrate is curled down by disposing an encapsulating layer on upper and lower portions of a lower substrate in a pad region .

Another object of the present invention is to provide an organic light emitting display device and an organic light emitting display device capable of minimizing a phenomenon in which a lower substrate is dried down by disposing an overcoat layer in a remaining region of the pad region except the upper region of the pad electrode, And to provide a device manufacturing method.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

An organic light emitting display according to an embodiment of the present invention is provided. The organic light emitting display includes a lower substrate. An inorganic layer is disposed on the lower substrate. The first pad electrode is disposed on the inorganic layer. The passivation layer is arranged to cover the side of the first pad electrode. The second pad electrode is disposed on the passivation layer and is electrically connected to the first pad electrode. The conductive film layer is disposed on the second pad electrode. The circuit board is disposed on the conductive film layer. An upper encapsulation layer is disposed over the passivation layer and the circuit board. The lower sealing layer is disposed under the lower substrate. In the organic light emitting diode display according to the embodiment of the present invention, the lower substrate in the pad region is provided with tensile stress, so that the curling of the lower substrate can be suppressed.

According to another aspect of the present invention, there is provided an organic light emitting display comprising: a pad region in which an upper encapsulation layer and a lower encapsulation layer are disposed; and an organic light emitting layer, in which an anode electrically connected to the thin film transistor and the thin film transistor, And an active region in which the device is disposed.

According to another aspect of the present invention, the second pad electrode is formed of the same material as the anode.

According to another aspect of the present invention, there is further provided an overcoat layer disposed so as to surround the side surface of the conductive film layer.

According to another aspect of the present invention, the overcoat layer is characterized by having a tensile stress.

According to another aspect of the present invention, the lower substrate is formed of an optically isotropic polyimide.

According to another aspect of the present invention, the thermal expansion coefficient of the lower substrate is larger than the thermal expansion coefficient of the inorganic layer.

According to another aspect of the present invention, the upper encapsulation layer and the lower encapsulation layer are made of the same material.

According to another aspect of the present invention, the upper encapsulation layer and the lower encapsulation layer are made of a transparent and non-viscous material.

According to another aspect of the present invention, the upper encapsulation layer and the lower encapsulation layer are made of resin.

According to still another aspect of the present invention, the upper sealing layer and the lower sealing layer have a tensile stress.

According to another aspect of the present invention, there is provided a method of manufacturing an organic light emitting display, comprising: disposing a material for an overcoat layer on an inorganic layer disposed on an active region and a pad region of a lower substrate; Forming an overcoat layer on the overcoat layer in the active area and forming a second pad electrode on the first pad electrode in the pad area, removing the overcoat layer to expose the overcoat layer, Forming an organic light emitting layer and a cathode on the anode; forming an encapsulating layer to cover the cathode; bonding the lower substrate and the upper substrate using an adhesive layer; Disposing a circuit board on the second pad electrode using the conductive film layer, forming a pad Forming an upper sealing layer on the overcoat layer of the station, and a step of forming the lower sealing layer at the bottom of the lower substrate in the pad area. According to another exemplary embodiment of the present invention, the overcoat layer may be disposed on the pad region except for the upper region of the pad electrode, thereby providing a tensile stress to the lower substrate by the overcoat layer, Can be minimized.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: forming a lower film layer under the lower substrate in the active region.

According to another aspect of the present invention, the maximum thickness of the lower sealing layer is equal to or less than the thickness of the lower film layer.

According to another aspect of the present invention, the maximum height of the upper sealing layer is lower than or equal to the height at which the upper substrate is disposed.

According to still another aspect of the present invention, the overcoat layer disposed in the pad region is characterized by having a tensile stress that counteracts the compressive stress of the lower substrate.

The details of other embodiments are included in the detailed description and drawings.

The present invention can produce an organic light emitting display capable of suppressing curling of a lower substrate by providing a tensile stress to a lower substrate having flexibility and having a compressive stress.

In addition, the present invention can provide an organic light emitting display device including a flat organic light emitting display panel by providing an overcoat layer on a pad region other than a region above the pad electrode to further provide a tensile stress to the lower substrate.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the specification.

1 is a schematic plan view for explaining an organic light emitting display according to an embodiment of the present invention.
2 is a cross-sectional view of the organic light emitting diode display cut along the line II-II 'of FIG.
FIG. 3 is a cross-sectional view of a surface of the organic light emitting display according to another embodiment of the present invention taken along line II-II 'in FIG. 1;
4 is a flowchart illustrating a method of manufacturing an OLED display according to another embodiment of the present invention.
5A to 5G are cross-sectional views illustrating a method of manufacturing an organic light emitting display according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, and the like disclosed in the drawings for describing the embodiments of the present invention are illustrative, and thus the present invention is not limited thereto. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Where the terms "comprises", "having", "done", and the like are used in this specification, other portions may be added unless "only" is used. Unless the context clearly dictates otherwise, including the plural unless the context clearly dictates otherwise.

In interpreting the constituent elements, it is construed to include the error range even if there is no separate description.

In the case of a description of the positional relationship, for example, if the positional relationship between two parts is described as 'on', 'on top', 'under', and 'next to' Or " direct " is not used, one or more other portions may be located between the two portions.

It will be understood that when an element or layer is referred to as being on another element or layer, it encompasses the case where it is directly on or intervening another element or intervening another element or element.

Although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical spirit of the present invention.

Like reference numerals refer to like elements throughout the specification.

The sizes and thicknesses of the individual components shown in the figures are shown for convenience of explanation and the present invention is not necessarily limited to the size and thickness of the components shown.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other partially or entirely and technically various interlocking and driving is possible as will be appreciated by those skilled in the art, It may be possible to cooperate with each other in association.

Various embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

1 is a schematic plan view for explaining an organic light emitting display according to an embodiment of the present invention. 2 is a cross-sectional view of the organic light emitting diode display cut along the line II-II 'of FIG. Referring to FIGS. 1 and 2, the OLED display 100 is divided into an active area A / A and a pad area P / A. Here, the pad region P / A surrounds the active region A / A.

1 and 2, the OLED display 100 includes a lower substrate 110, an inorganic layer 120, a thin film transistor (TFT), a passivation layer 141, A coating layer 143, a bank layer 145, an organic light emitting diode 150, an encapsulating layer 147, an adhesive layer 149 and an upper substrate 115. Although not shown in FIG. 1, a plurality of pixels are arranged in the active area A / A, and each of the pixels emits light independently. An inorganic layer 120 including a gate insulating layer 121 for insulating the gate electrode and the semiconductor layer on the lower substrate 110 and an interlayer insulating layer 123 for insulating the gate electrode from the source / (TFT) is disposed, and a passivation layer 141 is disposed to cover the thin film transistor TFT. An overcoat layer 143 for planarizing the upper portion of the thin film transistor TFT is disposed on the passivation layer 141 and an anode 151, an organic light emitting layer 152, and a cathode 153 are formed on the overcoat layer 143 The organic light emitting element 150 and the bank layer 145 are disposed. An encapsulating layer 147 is disposed on the cathode 153 of the organic light emitting diode 150 and a part of the bank layer 145. An adhesive layer 149 is disposed on the encapsulating layer 147 to form the upper substrate 115 And the lower substrate 110 are bonded to each other.

The active area A / A may be defined by the upper substrate 115. That is, the upper substrate 115 may be disposed only on the active area A / A and may be disposed on the adhesive layer 149 so as to completely overlap the active area A / A, And the end portion coincides with the boundary line between the active area A / A and the pad area P / A.

A lower film layer 171 is disposed under the lower substrate 110 in the active area A / A. When the OLED display 100 emits light in a top emission mode, the lower film layer 171 may be a back film, and the OLED display 100 may be a back emissive display, When light is emitted in a bottom emission mode, the lower film layer 171 may be a polarizing plate.

2, the OLED display 100 includes a lower substrate 110, an inorganic layer 120, a passivation layer 141, a pad electrode 130, a conductive film layer (not shown) 135, a circuit board 137, an upper encapsulation layer 161 and a lower encapsulation layer 163.

The lower substrate 110 is made of a transparent material having flexibility. For example, the lower substrate 110 is a substrate made of polyimide (PI). Here, the lower substrate 110 may be made of optically isotropic polyimide. The optically isotropic polyimide is a material having compressive stress, and the lower substrate 110 also has compressive stress. Further, the lower substrate 110 may be made of a material having a large thermal expansion coefficient. Specifically, the thermal expansion coefficient of the lower substrate 110 is larger than the thermal expansion coefficient of glass or metal.

An inorganic layer 120 disposed on the lower substrate 110 in the pad region P / A is disposed. The inorganic layer 120 includes a gate insulating layer 121 and an interlayer insulating layer 123. The gate insulating layer 121 and the interlayer insulating layer 123 are formed extending from the active region A / A.

The inorganic layer 120 is made of an inorganic material. Specifically, the gate insulating layer 121 and the interlayer insulating layer 123 are all made of an inorganic material. In addition, the gate insulating layer 121 and the interlayer insulating layer 123 may be made of the same material. For example, the gate insulating layer 121 and the interlayer insulating layer 123 may be composed of an insulating material such as silicon nitride (SiNx) and silicon oxide (SiOx). Here, the inorganic layer 120 may be made of a material having a thermal expansion coefficient lower than that of the lower substrate 110. Accordingly, the inorganic layer 120 expands less than the lower substrate 110 at a high temperature and shrinks less than the lower substrate 110 when it returns to a low temperature.

Referring to FIGS. 1 and 2, a pad electrode region PE / A is included in a pad region P / A. The pad electrode area PE / A is a region occupied by the pad electrode 130 in the pad area P / A, and the first pad electrode 131 or the second pad electrode 133 is disposed to cover the pad area P / A).

Referring to FIG. 1, a plurality of pad electrodes 130 may be disposed along at least one side of the active area A / A. As shown in FIG. 1, the plurality of pad electrodes 130 are spaced apart from each other and disposed in the pad region P / A.

Referring to FIGS. 1 and 2, the first pad electrode 131 is disposed on the inorganic layer 120 in the pad region P / A. Specifically, the first pad electrode 131 is disposed on the interlayer insulating layer 123 in the pad region P / A. The first pad electrode 131 is arranged to apply a voltage to the thin film transistor TFT disposed in the active area A / A. 2, the first pad electrode 131 is electrically connected to a wiring connected to a gate electrode, a source electrode, or a drain electrode of the thin film transistor TFT.

The first pad electrode 131 is made of a conductive material. Specifically, the first pad electrode 131 is made of the same conductive material as the source electrode or the drain electrode of the thin film transistor TFT in the active region A / A. For example, the first pad electrode 131 may be formed of a material containing at least one of molybdenum-titanium (MoTi) and copper (Cu).

The passivation layer 141 is disposed on the inorganic layer 120. The passivation layer 141 is disposed to cover the side of the first pad electrode 131. The passivation layer 141 may be made of an inorganic material such as the inorganic layer 120.

Referring to FIGS. 1 and 2, a second pad electrode 133 is disposed on the inorganic layer 120 in the pad region P / A. The second pad electrode 133 is arranged to be electrically connected to the first pad electrode 131 on the first pad electrode 131 in the pad region P / Is disposed so as to cover a part of the passivation layer 141. In addition, the second pad electrode 133 may be disposed to completely overlap the upper region of the first pad electrode 131. The second pad electrode 133 can define a pad electrode area PE / A and is electrically connected to the first pad electrode 131 in the pad electrode area PE / A.

The second pad electrode 133 may be formed of the same material as the anode 151. Specifically, the second pad electrode 133 is made of a conductive material and is made of the same material as the anode 151, such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide But is not limited to, a transparent conductive oxide (TCO) including zinc oxide, zinc oxide, tin oxide, and combinations thereof.

The conductive film layer 135 is disposed on the second pad electrode 133 in the pad region P / A. Specifically, the conductive film layer 135 is disposed in contact with the upper surface of the second pad electrode 133 in the pad electrode region PE / A. The conductive film layer 135 may be an adhesive made of a conductive material and may be electrically connected to the pad electrode 130. The conductive film layer 135 includes conductive particles and allows the circuit board 137 to be electrically connected to the pad electrode 130 through a conductive adhesive. For example, the conductive film layer 135 is made of a material in which polymer particles coated with metal particles are dispersed in an epoxy resin having an adhesive force.

The circuit board 137 is disposed on the conductive film layer 135 and electrically connected to the conductive film layer 135 to apply various voltages from the outside of the organic light emitting display panel to the active area A / Specifically, the circuit board 137 is provided with a metal wiring on an imide film, wherein the metal wiring can be a copper wiring.

The upper encapsulation layer 161 is made of a transparent and tacky free material. In addition, the upper sealing layer 161 may be made of an insulating material to prevent moisture permeation into the active area A / A. Specifically, the upper sealing layer 161 is made of a transparent and viscous resin.

The upper sealing layer 161 is made of a material having a tensile stress. Accordingly, the upper sealing layer 161 can provide tensile stress to the lower substrate 110 in the pad region P / A. Specifically, in the pad region P / A, compressive stress is applied to bend the lower substrate 110 downward, and the upper seal layer 161 can provide tensile stress to the upper portion of the lower substrate 110. That is, the phenomenon in which the lower substrate 110 is curled due to the compressive stress of the lower substrate 110 in the pad region P / A is caused by the compressive stress of the upper substrate layer 161 acting in the opposite direction to the compressive stress of the lower substrate 110 Can be suppressed by tensile stress.

Referring to FIG. 2, an upper encapsulation layer 161 is disposed on the passivation layer 141 and the circuit board 137. Specifically, the upper sealing layer 161 covers the upper portion of the passivation layer 141, the side of the second pad electrode 133, the side of the conductive film layer 135, and the side of the circuit board 137 in the pad region P / As shown in Fig. That is, the upper sealing layer 161 is made of a material having no viscosity and can be arranged to fill the pad region P / A except for the pad electrode region PE / A.

Referring to FIG. 2, the upper portion of the upper sealing layer 161 may include a curved surface. Since the upper sealing layer 161 is formed of resin, the shape of the upper sealing layer 161 shown in FIG. 2 is exemplary and may have various shapes. Specifically, the upper sealing layer 161 may be arranged to contact the adhesive layer of the active area A / A or the side surface of the upper substrate 115. Accordingly, the shape of the upper portion of the upper sealing layer 161 may be inclined to the active region A / A.

The maximum height of the upper sealing layer 161 may be lower than or equal to the height at which the upper substrate 115 is disposed. The height of the upper sealing layer 161 can be determined so as to alleviate steps in the process, and the height at which the upper sealing layer 161 is formed will be described later with reference to FIGS. 4 to 5G.

The upper sealing layer 161 can suppress the curling of the lower substrate 110 in the pad region P / A by the tensile stress. Specifically, the lower substrate 110 has a compressive stress directed downward of the lower substrate 110, and the upper sealing layer 161 has an upward tensile stress of the lower substrate 110. Accordingly, the tensile stress of the upper sealing layer 161 can prevent the lower substrate 110 from being curled down by offsetting the compressive stress directed downward of the lower substrate 110 in the opposite direction.

The lower encapsulation layer 163 may be composed of the same material as the upper encapsulation layer 161. That is, the lower sealing layer 163 may be made of an insulating material that is transparent, has no viscosity, and can prevent moisture permeation, and may be made of a material having a tensile stress.

Referring to FIG. 2, the lower sealing layer 163 is disposed under the lower substrate 110. Specifically, the lower sealing layer 163 is disposed on the lower side of the lower substrate 110 in the pad region P / A and on the side of the lower film layer 171 disposed in the active region A / A .

Further, the lower portion of the lower sealing layer 163 may include a curved surface. The lower sealing layer 163 may have a shape as shown in FIG. 2, but it is not limited thereto and may have various shapes. For example, the lower sealing layer 163 may be formed thicker on the side of the lower film layer 171 and thinner toward the edge of the pad region P / A.

The lower sealing layer 163 can prevent the lower substrate 110 from being bent upward due to the tensile stress of the upper sealing layer 161. [ That is, the lower sealing layer 163 is formed by compressive stress that directs the lower substrate 110 downward, and tensile stress that directs the lower substrate 110 upward, so that the lower substrate 110 can be flattened without being bent upward or downward. The equilibrium between the stresses can be matched. The lower sealing layer 163 may be disposed under the lower sealing layer 163 before the lower sealing layer 163 is disposed and may be suppressed by gravity so that the lower substrate 110 may not be curled down. The specific effects of suppressing the curling of the lower substrate 110 in accordance with the process arrangement will be described later with reference to FIGS. 4 to 5G.

In the OLED display 100 according to the embodiment of the present invention, the upper sealing layer 161 is disposed on the pad electrode 130 in the pad region P / A, The sealing layer 163 is disposed, and the curling phenomenon in the pad region P / A of the lower substrate 110 can be reduced. Specifically, the lower substrate 110 undergoes compressive stress due to a difference in thermal expansion coefficient between the lower substrate 110 and the inorganic layer 120 disposed on the lower substrate 110, and is bent downward from the pad region P / A. Thus, the lower substrate 110 is subjected to tensile stress so as to offset the compressive stress applied to the lower substrate 110. That is, the upper sealing layer 161 is disposed on the pad electrode 130 in the pad region P / A, thereby suppressing the phenomenon that the lower substrate 110 is curled downward. The lower sealing layer 163 is disposed below the lower substrate 110 to prevent the lower substrate 110 from being bent upward in the pad region P / A by the upper sealing layer 161. Accordingly, the compressive stress and the tensile stress acting on the lower substrate 110 in the pad region P / A are balanced so that the lower substrate 110 is kept flat and the curling of the lower substrate 110 is suppressed .

FIG. 3 is a cross-sectional view of a surface of the organic light emitting display according to another embodiment of the present invention taken along line II-II 'in FIG. 1; The organic light emitting display 300 of FIG. 3 is different from the organic light emitting display 100 of FIG. 1 in that the arrangement of the overcoat layer 343 in the pad region P / A and the shape of the upper sealing layer 361 are changed , And the other configurations are substantially the same, so redundant explanations are omitted.

Referring to FIG. 3, an overcoat layer 343 is disposed in the active area A / A and the pad area P / A. Specifically, the overcoat layer 343 is disposed on the passivation layer 141 in the remaining pad region P / A except for the pad electrode region PE / A. That is, the overcoat layer 343 is disposed so as to surround the side of the second pad electrode 133 and the conductive film layer 135 disposed in the pad electrode region PE / A. As the overcoat layer 343 is also disposed in the pad region P / A, a portion of the adhesive layer 349 may also be disposed on the planar overcoat layer 343.

The overcoat layer 343 is made of photoresist and may be made of a material having a tensile stress. Accordingly, the overcoat layer 343 may be disposed in the pad region P / A to provide tensile stress on the upper substrate 110. That is, the overcoat layer 343 is disposed in a region other than the pad electrode region PE / A in the pad region P / A to provide a tensile stress necessary for suppressing the phenomenon in which the lower substrate 110 is curled downward can do.

Referring to FIG. 3, an upper encapsulation layer 361 is disposed on the overcoat layer 343 and the circuit board 137 in the pad region P / A. Since the upper sealing layer 361 is made of a transparent and viscous insulating material having a tensile stress, the compressive stress applied to the lower substrate 110 in the pad region P / A is canceled, Can be suppressed. In particular, since the overcoat layer 343 also has a tensile stress, the upper encapsulation layer 361 can provide a strong tensile stress to the lower substrate 110 together with the overcoat layer 343. That is, the upper sealing layer 361 can efficiently provide tensile stress to the lower substrate 110 together with the overcoat layer 343 in a small amount.

The overcoat layer 343 is disposed on the pad region P / A except for the pad electrode region PE / A, and the overcoat layer 343 is formed on the overcoat layer 343 in the organic light emitting diode display 300 according to an exemplary embodiment of the present invention. The upper sealing layer 361 is disposed to more effectively cancel the compressive stress acting on the lower substrate 110. [ Specifically, the overcoat layer 343 is also disposed in the pad region P / A to planarize the pad region P / A so that the circuit board 137 and the upper encapsulation layer 361 can be easily disposed. In addition, since the overcoat layer 343 can also provide tensile stress to the lower substrate 110, it can provide greater tensile stress to the lower substrate 110 together with the upper sealing layer 361. Accordingly, even if the upper sealing layer 361 is formed to have a small thickness, it can provide a sufficient tensile stress to the lower substrate 110 together with the overcoat layer 343, thereby preventing the lower substrate 110 from being curled.

4 is a flowchart illustrating a method of manufacturing an OLED display according to another embodiment of the present invention. 5A to 5G are cross-sectional views illustrating a method of manufacturing an organic light emitting display according to another embodiment of the present invention. FIGS. 5A to 5G are process cross-sectional views illustrating a method of manufacturing the organic light emitting diode display 300 shown in FIG. 3, and overlapping descriptions of the components described with reference to FIG. 3 are omitted.

First, an overcoat layer material 383 is disposed on the inorganic layer 120 disposed in the active region A / A and the pad region P / A of the lower substrate 110 (S410).

5A, a lower substrate 110 is disposed on a glass substrate 389, and an inorganic layer 120 having a thermal expansion coefficient smaller than that of the lower substrate 110 is disposed on the lower substrate 110. A thin film transistor TFT is disposed on the lower substrate 110 in the active area A / A and a first pad electrode 131 is disposed on the inorganic layer 120 in the pad area P / A.

 The passivation layer 141 is made of an inorganic material and is conformally disposed along the top of the thin film transistor TFT so as to prevent moisture permeation from the active area A / A to the thin film transistor TFT. The passivation layer 141 is disposed to cover the side of the first pad electrode 131 in the pad region P / A.

Overcoat layer material 383 is disposed throughout active area A / A and pad area P / A. Specifically, an overcoat layer material 383 is disposed to planarize the passivation layer 141 and the first pad electrode 131 disposed on the inorganic layer 120.

Subsequently, an overcoat layer 343 is formed by removing the overcoat layer material 383 to expose the upper portion of the first pad electrode 131 disposed in the pad region P / A (S415).

Referring to FIG. 5B, the overcoat layer material 383 is partially removed to form an overcoat layer 343, and the overcoat layer 343 includes a contact hole. Specifically, the overcoat layer 343 includes a contact hole formed in the active region A / A toward the source electrode or the drain electrode of the thin film transistor TFT. In the pad region P / A, And a contact hole formed to correspond to the pad electrode region PE / A on the substrate 131. Here, the contact hole is formed by removing the overcoat layer material 383.

The overcoat layer material 383 may be patterned with a photoresist. Specifically, the overcoat layer 343 may be made of a positive photoresist. Accordingly, the contact hole generated in the active region A / A toward the source electrode or the drain electrode of the thin film transistor TFT is formed by forming the overcoat layer 343 in a constant taper shape.

If the upper sealing layer 361 is not disposed on the overcoat layer 343 in the pad region P / A, the lower substrate 110 receives compressive stress due to a difference in thermal expansion coefficient from the inorganic layer 120, (P / A). Specifically, since the thermal expansion coefficient of the lower substrate 110 is large and the coefficient of thermal expansion of the inorganic layer 120 is small, in the process of laminating the thin film transistor TFT and the organic light emitting element 150 in the active region A / A The lower substrate 110 can expand more than the inorganic layer 120 by the high temperature deposition process. When the substrate 100 is further cooled to a low temperature (for example, room temperature), the lower substrate 110 is contracted again, and undergoes compressive stress due to a difference in thermal expansion coefficient with the inorganic layer 120, In addition, the thickness of the structure laminated on the pad region P / A is thinner than that of the active region A / A due to few stacked structures on the pad region P / A. Accordingly, the lower substrate 110 can be easily dried down in the pad region P / A.

Here, since the overcoat layer material 383 has a tensile stress, the overcoat layer 343 can provide tensile stress to the lower substrate 110. That is, the overcoat layer 343 disposed in the pad region P / A provides a tensile stress acting in the direction opposite to the compressive stress to the lower substrate 110 to suppress the downward movement of the lower substrate 110 .

An anode 151 is formed on the overcoat layer 343 in the active region A / A and a second pad electrode 133 is formed on the first pad electrode 131 in the pad region P / A. (S420).

5C, the anode 151 is formed to be electrically connected to the source electrode or the drain electrode of the thin film transistor TFT in the active region A / A through the contact hole of the overcoat layer 343. Here, the anode 151 may be made of a conductive material. For example, the anode 151 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide, tin oxide, But not limited to, transparent conductive oxide (TransP / Arent Conductive Oxide (TCO)).

The second pad electrode 133 is disposed to be electrically connected to the first pad electrode 131 of the pad electrode region PE / A and the first pad electrode 131 on a part of the passivation layer 141. Here, the second pad electrode 133 may be formed simultaneously with the anode 151, and may be formed of the same material.

Subsequently, the bank layer 145 is formed on the overcoat layer 343 so as to cover the side of the anode 151 (S425). Then, an organic light emitting layer 152 and a cathode 153 are formed on the anode 151 (S430). Then, an encapsulating layer 147 is formed to cover the cathode 153 (S435). Subsequently, the lower substrate 110 and the upper substrate 115 are bonded together using the adhesive layer 349 (S440).

5D, an encapsulating layer 147, an adhesive layer 349, and an upper substrate (not shown) covering the organic light emitting device 150 and the organic light emitting device 150 are formed on the overcoat layer 343 in the active area A / 115 are formed. The organic light emitting diode 150 includes an anode 151, an organic light emitting layer 152 and a cathode 153. The organic light emitting diode 150 and the organic light emitting diode 150, the sealing layer 147 is formed. The sealing layer 147 may be formed of at least one of an inorganic layer and an organic layer. In some embodiments, the sealing layer 147 may be formed of a plurality of layers, and the plurality of layers may be formed by alternately stacking an inorganic layer and an organic layer. The adhesive layer 349 may be disposed on the encapsulating layer 147 such that the adhesive layer 349 is applied to the upper substrate 115 and then adhered to the lower substrate 110.

Subsequently, the circuit board 137 is disposed on the second pad electrode 133 using the conductive film layer 135 (S445).

Referring to FIG. 5E, the conductive film layer 135 and the circuit board 137 are disposed in the pad region P / A after the laminating process in the active region A / A is completed.

The conductive film layer 135 is a film-type adhesive containing conductive particles, and polymer particles coated with metal particles are dispersed in an epoxy resin having an adhesive force. The conductive film layer 135 is disposed on the second pad electrode 133 and then applies heat and pressure to bond the second pad electrode 133 and the circuit board 137. In addition, the conductive film layer 135 electrically connects the second pad electrode 133 and the circuit board 137 through the internal conductive particles.

The circuit board 137 is a substrate including a metal wiring, and is a substrate in which various wirings for supplying a voltage to be applied to the active area A / A are collected. The circuit board 137 is electrically connected to the pad electrode 130 by the conductive film layer 135.

Subsequently, an upper encapsulation layer 361 is formed on the overcoat layer 343 of the pad region P / A to cover at least a part of the circuit board 137 (S450).

Referring to FIG. 5F, an upper sealing layer 361 is formed on the overcoat layer 343 of the pad region P / A. That is, the upper sealing layer 361 is formed to cover the entire upper portion of the pad region P / A. Here, the upper sealing layer 361 may be coated on the pad region P / A by a coating method.

Since the upper sealing layer 361 is made of a material having a tensile stress, the upper sealing layer 361 can provide tensile stress to the lower substrate 110. That is, the upper sealing layer 361 in the pad region P / A provides a tensile stress to the lower substrate 110 together with the overcoat layer 343 to suppress the lower substrate 110 from being bent or curled downward .

Subsequently, the glass substrate 389 supporting the shape at the bottom of the lower substrate 110 is removed. Here, in order to remove the glass substrate 389, the organic light emitting display panel is turned over so that the upper substrate 115 faces downward and is fixed on a chuck (not shown). Thus, a laser beam is irradiated onto the glass substrate 389 to peel off the glass substrate 389.

Here, the maximum height of the upper sealing layer 361 from the lower substrate 110 may be equal to or lower than the height from the lower substrate 110 to the upper substrate 115. In this process, the pad region P / A may be tilted toward the upper substrate 115 due to the height difference between the upper substrate 115 and the upper sealing layer 361. The maximum height of the upper sealing layer 361 from the lower substrate 110 is equal to the height from the lower substrate 110 to the upper substrate 115. In the process of peeling the glass substrate 389, There may be no problem caused by the problem. For example, bubbles may not be generated between the sealing material in the pad region P / A and the adhesive layer 349 or the upper substrate 115. Since the upper sealing layer 361 is made of a transparent and viscous moisture-proof insulating material, the maximum height of the upper sealing layer 361 from the lower substrate 110 to the upper substrate 115 Air bubbles may not be generated between the upper sealing layer 361 and the adhesive layer 349 or the upper substrate 115 in the pad region P / A even if a step difference occurs in the lower substrate 110 .

Subsequently, a lower sealing layer is formed under the lower substrate in the pad region (S455).

Referring to FIG. 5G, a lower sealing layer 163 and a lower film layer 171 are formed under the lower substrate 110 on which the glass substrate 389 is removed. Here, after the glass substrate 389 is removed, the lower encapsulation layer 163 and the lower film layer 171 are disposed with the OLED display panel turned upside down. Specifically, the lower film layer 171 is disposed on the lower substrate 110 of the active area A / A while the organic light emitting display panel is turned upside down. On the lower substrate 110 of the pad area P / A, A lower sealing layer 163 is disposed. Here, the lower encapsulation layer 163 may be disposed before the lower film layer 171, and the lower film layer 171 may be disposed before the lower encapsulation layer 163. As the lower film layer 171 is disposed on the lower substrate 110 of the pad region P / A, the lower film layer 171 provides gravity to the lower substrate 110 of the pad region P / A Thereby preventing the lower substrate 110 from being curled toward the upper substrate 115.

The overcoat layer 343 is disposed in the pad region P / A except for the pad electrode region PE / A to form the upper encapsulation layer 361 and the lower encapsulation layer 362. In the method of manufacturing the organic light emitting display according to another embodiment of the present invention, Thereby suppressing the phenomenon in which the lower substrate 110 is curled downward together with the sealing layer 163. Specifically, the overcoat layer 343 also has a tensile stress, thereby providing a tensile stress in the opposite direction to the compressive stress on the lower substrate 110 in the pad region P / A together with the upper encapsulation layer 361. Accordingly, the compressive stress acting on the lower substrate 110 is canceled by the tensile stress, and the lower substrate 110 is prevented from being curled downward. Further, the compressive stress and the tensile stress acting on the lower substrate 110 in the pad region P / A can be balanced by the upper encapsulation layer 361 and the overcoat layer 343 together with the lower encapsulation layer 163 In this case, the lower substrate 110 can be kept flat.

Also, in the method of manufacturing an organic light emitting diode display according to another embodiment of the present invention, in the step of removing the glass substrate 389 by the upper sealing layer 361 made of an insulating material which is transparent, Air bubbles are not generated between the upper sealing layer 361 and the upper substrate 115 and the adhesive layer 349.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those embodiments and various changes and modifications may be made without departing from the scope of the present invention. . Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100, 300: organic light emitting display
110: Lower substrate
115: upper substrate
120: inorganic layer
121: Gate insulating layer
122: interlayer insulating layer
130: pad electrode
131: first pad electrode
133: second pad electrode
135: Conductive film layer
137: circuit board
141: Passivation layer
143, 343: overcoat layer
145: bank layer
147: seal layer
149, 349: Adhesive layer
150: Organic light emitting device
151: anode
152: organic light emitting layer
153: cathode
161, 361: upper sealing layer
163: Lower sealing layer
171: Lower film layer
383: Material for overcoat layer
389: glass substrate

Claims (16)

A lower substrate;
An inorganic layer disposed on the lower substrate;
A first pad electrode disposed on the inorganic layer;
A passivation layer disposed to cover a side of the first pad electrode;
A second pad electrode disposed on the passivation layer and electrically connected to the first pad electrode;
A conductive film layer disposed on the second pad electrode;
A circuit board disposed on the conductive film layer;
An upper encapsulation layer disposed on the passivation layer and the circuit board; And
And a lower sealing layer disposed under the lower substrate. The method according to claim 1,
A pad region in which the upper encapsulation layer and the lower encapsulation layer are disposed; And
And an active region in which an anode, an organic light emitting layer, and a cathode, which are electrically connected to the thin film transistor, and an organic light emitting element in which a cathode is sequentially stacked, are disposed on the lower substrate. 3. The method of claim 2,
And the second pad electrode is made of the same material as the anode. The method according to claim 1,
And an overcoat layer disposed to surround the side surface of the conductive film layer. 5. The method of claim 4,
Wherein the overcoat layer has a tensile stress. The method according to claim 1,
Wherein the lower substrate is made of optically isotropic polyimide. The method according to claim 6,
Wherein the thermal expansion coefficient of the lower substrate is larger than the thermal expansion coefficient of the inorganic layer. The method according to claim 1,
Wherein the upper encapsulation layer and the lower encapsulation layer are made of the same material. 9. The method of claim 8,
Wherein the upper encapsulation layer and the lower encapsulation layer are made of a transparent and non-viscous material. 9. The method of claim 8,
Wherein the upper encapsulation layer and the lower encapsulation layer are made of resin. 9. The method of claim 8,
Wherein the upper sealing layer and the lower sealing layer have a tensile stress. Disposing a material for an overcoat layer on an inorganic layer disposed in an active region and a pad region of a lower substrate;
Forming an overcoat layer by removing the overcoat layer material to expose an upper portion of the first pad electrode disposed in the pad region;
Forming an anode on the overcoat layer in the active region and forming a second pad electrode on the first pad electrode in the pad region;
Forming a bank layer on the overcoat layer to cover the side of the anode;
Forming an organic light emitting layer and a cathode on the anode;
Forming an encapsulation layer to cover the cathode;
Attaching the lower substrate and the upper substrate using an adhesive layer;
Disposing a circuit board on the second pad electrode using a conductive film layer;
Forming an upper encapsulation layer on the overcoat layer of the pad region to cover at least a portion of the circuit board; And
And forming a lower sealing layer below the lower substrate in the pad region. 13. The method of claim 12,
Further comprising: forming a lower film layer below the lower substrate in the active region. 14. The method of claim 13,
Wherein the lower sealing layer has a maximum thickness equal to or smaller than a thickness of the lower film layer. 13. The method of claim 12,
Wherein a top height of the upper sealing layer is lower than or equal to a height at which the upper substrate is disposed. 13. The method of claim 12,
Wherein the overcoat layer disposed in the pad region has a tensile stress that counteracts the compressive stress of the lower substrate.

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